There are some really great entries appearing on the SQL Server 2005 Best Practices website. I just noticed this web page which discusses, amongs other things, some new features in SP2 like the vardecimal storage format and LOGON triggers. Take a look:
Top 10 Hidden Gems in SQL Server 2005 http://www.microsoft.com/technet/prodtechnol/sql/bestpractice/gems-top-10.mspx.
I also like the SQL Server 2005 Script Repository http://www.microsoft.com/technet/scriptcenter/scripts/sql/sql2005/default.mspx?mfr=true which provides links to some really useful scripts.
Service pack 2 for SQL Server 2005 is now available - all the details are here http://www.microsoft.com/technet/prodtechnol/sql/2005/downloads/servicepacks/sp2.mspx.
We can expect the RTM release of Service Pack 2 for SQL Server 2005 very very soon. In the meantime, please take a look at the updated readme file (dated 9th Jan 2007) 'Whats new in SQL Server 2005 SP2' which is available here: http://download.microsoft.com/download/2/b/5/2b5e5d37-9b17-423d-bc8f-b11ecd4195b4/WhatsNewSQL2005SP2.htm (this has continually been updated in line with the fixes and changes which are being made).
Here are some of my favourite changes/additions: